Manufacturing methods and devices have been developed to produce plastic bags in economical fashion. Such production methods are often highly automated and are capable of producing bags in large commercial quantities.
One type of bag making method that has been in use manufactures plastic bags from an elongate web of plastic material and a closer tape. The web of plastic material is folded lengthwise to form a web of folded plastic having a pair of free ends. The closer tape is brought into position adjacent the elongate web such that depending flanges of the closer tape are placed in overlapping relationship with the free ends of the elongate web. The flanges are then welded to the free ends by applying heat thereto. After the closer tape is secured to the free ends of the elongate web, slider closure members are installed onto the closer tape. Thereafter, the closer tape is embossed at spaced locations thereof to produce end stops. The elongate web is then simultaneously severed and sealed at the spaced locations by a hot knife to form individual bags.
While the foregoing production method has been effective to economically produce plastic bags on a commercial scale, it has been found that some bags produced in this manner can leak at a location adjacent the end stops. Still further, as with any production process, there exists the possibility that one or more components of the production line may not work as intended, thereby leading to the production of faulty bags. In such an event, it may be difficult or impossible to identify the production line that produced the faulty bag.